Gravekeeper's Servant is a Continuous Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Gravekeeper's Servant is Unlimited.
YGOPRODeck lists Gravekeeper's Servant for these formats: GOAT, OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
Gravekeeper's Servant belongs to the Gravekeeper's archetype—use that tag when searching for engine pieces and tech options.
A listed print of Gravekeeper's Servant appears in Dark Beginning 1 (DB1-EN017) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Gravekeeper's Servant is about $0.05 on Cardmarket (prices change frequently).
